﻿
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;


namespace Demo04
{
    class SumUtils
    {
       
        public int Sum(int i1, int i2)
        {
            return i1 + i2;
        }
        public double Sum(double d1, double d2)
        {
            return d1 + d2;
        }
        public string Sum(string str1, string str2)
        {
            return str1 + str2;
        }
        public int Sum(int num)
        {
            int Sum = 0;
            for (int i = 1; i < num; i++)
            {
                Sum += i;
            }
            return Sum;
        }
    }
}
